This invention relates to an instrument for applying a surgical clamp to an internal anatomical structure, usually but not limited to tubular structures more generally referred to as lumens. More specifically, it relates to an endoscopic applier for applying and retrieving a commonly known clamp, conventionally referred to as a "bulldog clamp".
Bulldog clamps are surgical clamps for temporarily occluding numerous kinds of bodily vessels and tubular organs, for example, blood vessels, bowel, ducts, urethra, and the like. These clamps can also be used for clamping other anatomical structure such as the lung, liver or adnexa, where it is often necessary to clamp not only for occlusion, but also for retraction. The occlusion of these anatomical structures, especially tubular structures, is often necessary during surgery to prevent leakage of lumen contents at the surgical site.
One of the chief characteristics of bulldog clamps is that they are designed for temporary clamping only. In other words, the clamp is intended to clamp a structure, e.g. occlude a vessel or tubular organ, while the surgery is being performed, and then it is subsequently removed from the occluded vessel or organ when the surgery is completed. Bulldog clamps have been known for years. See, for example, the Codman & Shurtleff Product Catalogue of 1990, which illustrates a variety of bulldog clamps for cardiovascular and thoracic surgical applications. Other examples of these clamps abound. Vascu-Statt.RTM. disposable bulldog clamps are described in a catalogue published by Scanlan International in 1991. Bulldog clamps come in a variety of sizes and configurations, and the clamping force can vary with the clamp design as well.
In order to facilitate the ability to drop off the bulldog clamp after it is clamped about the vessel or tubular organ, and to thereafter grasp and remove the clamp from the vessel or organ following the surgical procedure, the clamp must possess some kind of configuration in addition to its clamping jaws. Typically, the clamp includes a spring loaded handle mechanism for grasping the clamp and for providing the opposing jaw clamping force. More specifically, it has a self-contained spring element in its handle for providing the constricting force to the desired vessel or tubular organ.
While the current conventional design for bulldog clamps has worked well for surgeons in open surgery, modifications to the existing clamps have been necessary for their adaptation to endoscopic surgery. Endoscopic surgery is surgery performed through small ports or openings in the body with the aid of special equipment and surgical instrumentation to allow the surgeon to perform the surgery while observing his operative technique on a video monitor. The small openings are typically made using a trocar, which is a puncturing instrument for providing access through the body wall to the surgical site.
In open surgery, ratcheting scissor-handled type clamps have often been used rather than bulldog clamps. These scissor-handled clamps use the surgeon's hand force and a ratchet mechanism to apply and retain the clamping force. However, such clamps cannot fit conveniently down trocars. Therefore, with the advent of endoscopic surgery, ratcheting ring-handled clamps, especially designed for endoscopic use, were developed. Unfortunately, these clamps require full-time dedicated trocar ports, thus limiting the number of other instruments which the surgeon can introduce at any one time when the number of trocar ports remain constant.
Since drop-off bulldog clamps provide a tremendous advantage over conventional, scissor-handled clamps during endosurgery, a challenge has been how to introduce these clamps into the body, clamp them onto the desired anatomical structures and in the desired orientation, free the access port for other uses, and then retrieve them through a port when their function is fulfilled. Therefore, it has become necessary to develop a suitable endoscopic applier to apply such drop-off bulldog clamps.
Fortunately, design engineers have begun to rise to the challenge of designing an endoscopic applier to apply and subsequently remove bulldog clamps endoscopically. These applier designs have also taken into consideration some of the modifications needed to the clamp itself for proper functioning with the applier. A good example of such an applier/clamp combination is described in a catalogue published by Birtcher/SOLOS in 1992, which illustrates an applier for the G.I.-1085 Bowel Bulldog Clamp with 40 mm jaw. This applier can be removed from the surgical access port after the clamp has been applied to a vessel. The applier has a palm-actuated handle which causes a camming tube located inside a longitudinal shaft to move distally. The camming tube urges a pivoting jaw toward an opposed fixed jaw. A pair of cylindrical pins are displayed on the inner surfaces of the jaws for securing the clamp. The clamp has a hole through its grip or handle portion for receiving the cylindrical pins (unlike conventional clamps used for open surgery which do not have such a hole). When the jaws of the applier are closed, the jaws of the clamp are correspondingly biased open for clamping about a vessel. The shaft of the applier can rotate, and the clamp can pivot about the cylindrical pins of the jaws to provide variable positioning of the clamp at the surgical site.
A similar device is described in U.S. Pat. No. 4,706,668. This patent discloses an aneurysm clip plier. The plier has a hollow barrel terminating at its distal end with a Y-shaped clip grip. This grip has two opposed arms, and each arm has a projection for engaging corresponding dimples in the clip. The opposed arms of the Y-shaped grip are forced towards each other to open the clip for application to a vessel when a pusher bar is forced against the grip. The pusher bar is activated when a trigger on the handle of the plier is squeezed.
While the art has illustrated certain advances in the design of bulldog clamps and applier mechanisms for using such clamps during endoscopic surgical procedures, a significant drawback with these appliers still exists. Although the appliers which have been described provide the ability to rotate the clamp about the axis of the shaft of the applier, and to allow pivoting of the clamp within the jaws of the applier, the surgeon is unable to pivot the clamp within the jaws of the applier without using another instrument, or alternatively, without pushing the clamp against adjacent bodily anatomy. Obviously, this can present a tremendous inconvenience for the surgeon, who would much prefer having the ability to "steer" the clamp on the applier without these restraints.
The ability of the surgeon to pivot the bulldog clamp on the applier during use should not be underestimated. It is often critical during surgery to precisely position the clamp on the tubular organ, vessel, or any other structure desired to be occluded or clamped. This requires the corresponding ability of the surgeon to properly angulate the clamp when the applier is placed through the small access opening or port during endoscopic surgery. Likewise, it is necessary following removal of the clamp from the vessel or organ to have the ability to align the clamp with the axis of the longitudinal shaft of the applier to facilitate its removal from the body cavity.
One attempt to address the need for pivoting action of a surgical article within the jaws of an endoscopic applier is the development of "articulating" appliers. An articulating applier is an applier whose distal end is capable of articulating from the longitudinal axis of the shaft of the applier up to or even more than 90.degree., similar to the manner in which a knee joint articulates. While this may address needed problems in many instances, the length of that portion of the shaft of the applier distal to the articulating joint must have a minimum length for clearance within the limited volume of space available in endosurgical procedures.
In view of the deficiencies in the designs for appliers for bulldog clamps, what is needed is an endoscopic applier for a bulldog clamp, which not only can readily place and remove the clamp during endoscopic surgery, but also allows the surgeon to pivot the clamp within the jaws of the applier without altering the direction of any portion of the longitudinal shaft of the applier, More importantly, it would be most beneficial if the ability to "steer" the bulldog clamp could be accomplished without requiring the use of another instrument or the need to push the clamp against adjacent bodily tissue for the desired movement.